Const enums and optimization in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a const enum named Colors.

Typescript

const enum [1] {
  Red,
  Green,
  Blue
}

Drag options to blanks, or click blank then click option'

AEnumColors

BColorList

CPalette

DColors

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different name than the one declared.

Forgetting to use 'const' before enum.

The enum name should be Colors as declared.

2fill in blank

medium

Complete the code to access the enum value for Green.

Typescript

const greenValue = Colors.[1];

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ABlue

BGreen

CRed

DYellow

Attempts:

3 left

💡 Hint

Common Mistakes

Using a member name that does not exist in the enum.

Using incorrect casing for the member name.

Accessing the Green member of the Colors enum returns its value.

3fill in blank

hard

Fix the error in the code to correctly use a const enum value in a function.

Typescript

function getColorName(color: Colors): string {
  return color === Colors.[1] ? 'Green' : 'Unknown';
}

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ABlue

BRed

CGreen

DYellow

Attempts:

3 left

💡 Hint

Common Mistakes

Using a member that does not match the returned string.

Using a non-existent enum member.

The function compares the input to Colors.Green to return the correct name.

4fill in blank

hard

Fill both blanks to create a const enum and use its value in a variable.

Typescript

const enum [1] {
  Small = 1,
  Medium = 2,
  Large = 3
}

const sizeValue = [2].Medium;

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ASizes

BColors

DShapes

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the enum declaration and usage.

Using unrelated enum names.

The enum is named Sizes and the variable accesses Sizes.Medium.

5fill in blank

hard

Fill all three blanks to declare a const enum, assign a value, and compare it in a condition.

Typescript

const enum [1] {
  Low = 0,
  Medium = 1,
  High = 2
}

const currentLevel = [2].High;

if (currentLevel === [3].High) {
  console.log('High level reached');
}

Drag options to blanks, or click blank then click option'

APriority

DLevel

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for enum declaration and usage.

Mismatching enum names in condition and assignment.

The enum is declared as Level, but the variable and condition use Priority, which is incorrect. The correct consistent name is Priority for all blanks except the declaration which should be Level. The correct answer uses Level for declaration and Priority for usage, which is inconsistent. The correct consistent name for all is Priority. Here, the blanks are filled to show the correct usage with Priority.